I don't believe ALL the craft are merely materialized demons. I don't belivee ALL ET's are merely demons in bioengineered bodies though it appears that plenty of greys may well be.
I do believe that virtually all the better known races of ET's are IN CAHOOTS with the Father of Lies toward coercing the world's citizens into the evil, tyrannical world government headed by the AC.
The greys are all future naturalized citizens who are being brainwashed into becoming Democratic voters, because soon that will be the only way they can win elections.